Antenna System

ABSTRACT

A multi-band low-profile, low-volume two-way mobile panel array antenna system is described. Operation of the antenna may automatically switch between bands based on various user-entered parameters.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.13/048,550, filed Mar. 15, 2011, entitled “Antenna System”, which is ais a continuation-in-part of copending U.S. application Ser. No.13/030,866, filed Feb. 18, 2011, entitled “Applications for Low ProfileTwo-Way Satellite Antenna System, which is a continuation of U.S.application Ser. No. 11/647,576 (the '576 Application), filed Dec. 29,2006, which is a continuation-in-part of U.S. application Ser. No.11/320,805 (the '805 Application), filed Dec. 30, 2005, and which claimspriority under 35 U.S.C. §119(e)(1) to U.S. Provisional Application No.60/650,122, filed Feb. 7, 2005; the '805 Application also claimspriority under 35 U.S.C. §120 as a continuation-in-part to U.S.application Ser. No. 11/074,754, filed Mar. 9, 2005, U.S. applicationSer. No. 11/071,440, filed Mar. 4, 2005, U.S. application Ser. No.10/498,668, filed Dec. 17, 2002, and U.S. application Ser. No.10/925,937, filed Aug. 26, 2004; the '576 Application is also acontinuation-in-part of U.S. application Ser. No. 10/752,088, filed Jan.7, 2004, U.S. application Ser. No. 11/374,049, filed Mar. 14, 2006, andU.S. application Ser. No. 11/183,007, filed Jul. 18, 2005. The contentsof the above cases are hereby incorporated by reference as nonlimitingexamples of one or more features described herein. The presentapplication also claims priority to U.S. Provisional Application No.61/314,066, entitled “Antenna System” and filed on Mar. 15, 2010, thecontents of which are hereby incorporated by reference as a non-limitingexample of the system described herein.

FIELD OF ART

The features described herein relate generally to wirelesscommunications, such as satellite communications.

BACKGROUND

Demand for telecommunication services is constantly increasing, as moreand more users seek more and more convenience in accessing information.Cellular telephones and smartphones have allowed users to remain incontact with wired networks from distant locations. Mobile satellitereceivers are also in use to provide similar connectivity via satellite.Different communication networks often require different transmissionand reception equipment, and there remains an ever-present need forusers to maximize the flexibility of the equipment that they use.

SUMMARY

The present application relates generally to offering an antenna systemthat can be configured to automatically switch between disparate typesof wireless network communications.

In some embodiments, an antenna system may include a flat panel arraymounted on a rotatable assembly, with control circuitry and motors totrack satellites using one or more frequency bands. The system may beconfigured to automatically switch between the various bands based onuser-defined parameters.

The various user defined parameters may include signal strength,geographic position, satellite look angle, bandwidth, time of day, costof network, application or data type, etc.

Other details and features will also be described in the sections thatfollow. This summary is not intended to identify critical or essentialfeatures of the inventions claimed herein, but instead merely summarizescertain features and variations thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

Some features herein are illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings and in whichlike reference numerals refer to similar elements.

FIG. 1 illustrates an example radome-covered antenna assembly.

FIGS. 2 a & b illustrate the FIG. 1 example, with the radome removed.

FIGS. 3 a & b illustrate closer views of a flat panel array shown inFIGS. 2 a & b.

FIG. 4 illustrates a closer view of a rotatable assembly.

FIG. 5 illustrates a closer view of a block upconverter.

FIG. 6 is a block diagram illustrating components of an antennaassembly.

FIG. 7 is a block diagram illustrating tracking components of an antennaassembly.

FIG. 8 illustrates an example process for providing parameters andswitching between bands of operation.

DETAILED DESCRIPTION

FIG. 1 illustrates an example physical configuration of a low-profile,low volume, switchable band antenna assembly suitable for two-way usefor portable satellite communications on-the-move (e.g., mounted on amoving vehicle). Such an antenna can support various data rates, such as64 kbps transmit and 2 Mbps receive.

The antenna assembly 100 may include a radome cover enclosure 101 thathouses various antenna components described herein. The cover 101 may beformed using a weatherproof material that passes electromagneticfrequencies in the desired bands of operation, and can serve as aprotective housing for the antenna assembly 100. Example componentshoused within the cover 101 are discussed further below with respect toFIGS. 2 a-3 b. For example, the enclosure 101 can have a generallycylindrical shape, and be shorter than thirteen inches in diameter(e.g., it can have a twelve-inch or 311 mm diameter) and ten inches inheight (e.g., it can have an eight-inch or 200 mm height).

The cover 101 and the components housed within may be mounted on arotating platform assembly 102. The rotating assembly 102 may be motordriven to rotate about a vertical axis to adjust the azimuth of theassembly to track one or more signal sources, such as satellites.Example components of the assembly 102 are discussed further below withrespect to FIG. 4.

The rotating assembly 102 may be mounted onto a block upconverter (BUC)103. The BUC 103 may include frequency upconversion circuitry to convertsignals from one frequency to a higher frequency for transmission.Example features of the BUC 103 are discussed further below with respectto FIG. 5.

FIGS. 2 a & b illustrate an example of the assembly 100 with the cover101 removed. As depicted, the antenna may include one or more flat panelarrays 200. The array 200 can include a series of antenna transmissionand reception elements, such as a printed circuit design with parasiticpatches to extend the frequency response and provide wide bandcapability. The panel configuration allows it to maintain a flat profilewith low volume, which can be advantageous for mounting on the exteriorof vehicles.

The panel array 200 may be a bidirectional Ku-band array panelconfigured to communicate with satellites in the Ku-band (e.g., 14.0 to14.5 GHz and 10.9 to 12.7 GHz), a Ka-band panel configured tocommunicate with satellites in the Ka-band (e.g., 26.5 to 40 GHz), orany other desired panel for a desired frequency band. In someembodiments, the array 200 is configured for a high frequencytransmission such as the Ku and Ka bands discussed above. High frequencybands may be those above 2 GHz.

In addition to the high-frequency panel, the antenna assembly 100 mayinclude one or more low frequency antennas 201. The low-frequencyantenna 201 may be, for example, an L-band panel configured tocommunicate with satellites in the L-band (e.g., IMMARSAT 1525 to 1646.5MHz). The assembly 100 or antenna panel 200 may also include antennasfor communicating with terrestrial networks, such as wireless cellulartelephone networks, WiMax wireless computer networks, and the like.

The operation of the antenna 100 may be controlled by a controllercircuit 202, which can include one or more microprocessors and one ormore memories (e.g., flash memories, ROMs, removable media, etc.)storing computer-executable instructions that, when executed by the oneor more microprocessors, cause the antenna assembly 100 and itscomponents to perform in the various manners described herein. Thecontroller circuit 202 may include one or more external interfaces, suchas audio/visual interfaces (displays, speakers, touch screens, etc.),computer monitor interfaces, user input device interfaces (e.g.,keyboards, mice, touch screens, etc.). The interfaces may also includeinterfaces for external control, such as an Ethernet interface,Universal Serial Bus (USB), a serial interface, or any other desireddevice interface. The circuit 202 may also include a series of coaxialcable interfaces 203, which can be connected to a modem device totransmit and receive signals for a customer device. For example, theantenna may be connected to one or more satellite modems, which canconvert the antenna's signals into a desired digital interface, such asan Internet Protocol interface. User devices can connect to the IPinterface, and can use the modem to send and receive data with otherdevices on the Internet.

The controller circuit 202 can also cause the assembly to rotate toadjust azimuth, and elevate the panel 200 to adjust elevation by tiltingthe panel about an elevation mount 209, to allow the panel 200 to trackone or more satellites. To do so, the assembly may include one or moremotors 204 (e.g., motors 204 can include azimuth and elevation motors),belts 205, pulleys 206, etc.

The antenna assembly 100 can also include a polarization circuit 207,which can be configured to adjust the polarization of signals fortransmission and/or reception. The assembly 100 can also include aglobal positioning system (GPS) 208, which can be configured to receivesatellite timing signals and triangulate the position of the assembly100. This circuit can further include internal 3-axis gyroscopes andcorresponding orientation circuitry to detect acceleration of theassembly 100 as it moves and turns, as well as 2-axis inclinometers.

FIGS. 3 a & b illustrate isolation views of the front and rear of anexample panel 200. In the rear view, a gyroscope circuit 301, RFcombiner 302, and diplexer circuitry 303 can be seen.

FIG. 4 illustrates a closer view of the rotating assembly 102. Therotating assembly 102 may include a rotating platform 401 configured torotate about a central axis 402 under the control of an azimuth motor204 and its corresponding belt and pulley. The antenna array panel 200may be mounted to the rotating assembly. A dual channel rotary joint 403may be used to allow wiring and/or signals from above the rotatingplatform to pass through the bottom cover and reach components locatedunder the rotating assembly 102, such as the BUC 103.

FIG. 5 illustrates a closer view of the BUC 103. The BUC 103 can beconfigured to upconvert signals to higher frequency bands and amplifyingthem for transmission, such as converting L band to Ku band. It can beshaped to fit under the radome 101, and can have a thin profile (e.g., 2cm). The BUC 103 may include input and output connectors 501, to carrysignals from and to the panel 200, DC power input 502, cooling fins 503and various mounting holes 504 to allow it to be mounted to theunderside of the rotating assembly 102.

FIG. 6 illustrates a block diagram representation of the exampleassembly shown in FIGS. 1-5. Element numerals are repeated for commonelements. Additional elements are shown as well. For example, the L-bandpatch 601 may be a printed circuit antenna element of the L-band antenna201, and can be used for transmission and reception on the L-band (orany other desired low frequency band). A series of duplexers 602 a & b(which can be diplexers configured for signaling) can be used to isolatethe up and down frequencies for the two-way transmission (which can besimultaneously carried out), while a low noise amplifier 603 can be usedto amplify the received signal for further processing. This L-bandportion (the top left portion of FIG. 6) can be connected to a sourceselection switch 604. The source selection switch 604 can be a manuallyor electronically controlled switch, and can selectively connect theL-band portion to the rest of the antenna and, ultimately, to userdevices to allow those devices to receive L-band signals. If manual, theswitch 604 can be positioned anywhere on the antenna, such as on anouter surface of the control circuit 202.

The other side of the source selection switch 604 can be connected toreception circuitry for the panel 200, which in some examples can be aKu or Ka band panel. The panel 200 may include a diplexer 605 forseparating transmission and reception frequencies. The reception side ofthe diplexer 605 may be connected to a receive side 207 a ofpolarization control circuit 207 and then to low noise block (LNB) 606,which can process received signals to supply them to the receiveselection switch 604.

The diplexer 605 may also include a transmission side connected to atransmission side 207 b of the polarization control 207.

A dual channel rotary joint 403 may have an L-band side and a Ku-bandside connected to the switch 604 and transmit polarization control 207,respectively (left and right in FIG. 6). The dual channel rotary joint403 allows the wiring for these signals to pass through the rotatingplatform to other components in the system, such as interfaces tomodems. On the left, the L-band side may connect to another switch 607.Similar to the switch 604, switch 607 also selectively switches betweenthe L-band interface 610 and Ku-band (in this example) receptioninterface 611. On the right hand side, a Ku-band transmission interface612 may receive signals to be transmitted in the Ku-band, and the BUC103 may upconvert those signals for transmission by the panel 200.

FIG. 7 illustrates an example block configuration for using the antennacomponents described above. Beginning at the bottom, various pieces ofuser equipment (e.g., computers) may connect to a modem 701, which inturn can be connected to the BUC 103 for higher band (e.g., Ku-band)transmissions, and to the antenna assembly 100 directly for othercommunications. The controller 202 may control the operation of theantenna through the execution by a processor 202 a of instructionsstored in a memory 202 b, and antenna panel 200 may receive controls forazimuth, elevation and polarization adjustments to track a satellite.Inputs from an inclinometer, gyroscope and GPS may also be used for thistracking.

FIG. 8 illustrates an example process for using the antenna systemdescribed above. The process can be carried out by the antenna's controlcircuit 202 and its processor(s). In step 801, the antenna system mayinitially receive switching parameters. It may do this by, for example,receiving user input from a computer connected to the antenna'scontroller board 202 using any of the interfaces discussed above (e.g.,via an Ethernet interface). The controller circuit 202 may support anIP-based interface, allowing user computers to view and modify usersettings and parameters.

The user may, for example, view a user interface identifying variousparameters that can be adjusted and/or weighted for switching betweenthe bands supported by the antenna for the desired one- or two-waycommunication. For example, if the antenna supported L-band, Ka-band andterrestrial cellular, the parameters may identify signal conditions andpriorities in which each is to be used. For example, the parameter canindicate that L-band is given first priority, cellular terrestrial isnext, and Ka-band is last, due to relative costs of using each band forcommunication. The parameter can also specify minimum signal strengthvalues or signal-to-noise ratios in which each band is acceptable.

The parameters can indicate that the priorities can be different indifferent geographic locations. For example, if terrestrial cellular isextremely expensive in some regions of the world, the priority forcellular may be moved to be last, with Ka-band moving up.

The parameters can indicate that the priorities can be different atdifferent times of day. The parameters may indicate a security level ofdifferent bands and/or geographic locations. For example, the user mayknow that certain bands (or services on bands) have stronger encryptionthan other services or bands, and those security levels can alter thepriority of the available bands. The parameters may also be adjustedbased on known jamming capability of enemy forces. For example, if it isknown that enemy forces in a given geographic area are actively jammingin the L-band, then the priority for that area can lower the priority ofthe L-band. The look angle to a particular satellite may also be aparameter. For example, a satellite that is lower in the horizon is morelikely to suffer eventual interference, even if the current signal isstrong, so the user may choose to indicate that satellites having a morevertical look angle should be given higher priority. The look angle canbe based on the GPS position and the particular locations of thesatellites that offer the different bands.

Another parameter may be based on available bandwidth in each band. Forexample, different bands may be more congested than other bands, and canconsequently offer different amounts of available bandwidth. Theparameters may indicate that a certain minimum amount of bandwidth mustbe available for a particular band to be used, and if the availablebandwidth in that band falls below the minimum amount, then the band maybe switched for a different band. The same is true for differentservices within the same band (e.g., two competitors that offercommunication service in the L-band).

Another parameter may be the application being used, or data type beingsent. For example, if the customer device only needs to send a smallamount of data, such as a text message, then a lower-bandwidth link suchas some found in the L-band may be more appropriate. Similarly, if thecustomer device needs to send a large amount of data, such as amultimedia streaming video, then a higher-bandwidth band like Ku, Ka orX may be more appropriate. Based on the desired data to be sent, thepriorities for the different bands can be altered.

From the above, it should be clear that the various user parameters canbe modified and combined in any desired manner, to result in any desireduser profile of prioritizing bands. When the user is finished editingthe parameters, the various parameters may be stored in the controller'smemory, and the process can proceed to step 802.

In step 802, the antenna system (or the controller) can proceed withconducting transmission and reception for the various connected devices(e.g., consumer devices or modems 701 that request to receive ortransmit information). In some embodiments, the operation of the systemcan be completely autonomous, once the parameters are established.

In step 803, which can occur continuously and/or simultaneously withstep 802, the antenna system can measure values that affect theparameters set in step 801. For example, the system can measure signalstrengths and signal-to-noise ratios for the various bands. It can alsodetermine the antenna's current location using the GPS component.

In step 804, the system can determine whether the measured values shouldresult in a change of the band. For example, if the signal-to-noiseratio for the L-band falls below its floor threshold, the antennacontroller may consult the user's parameters and determine that itshould now switch from the L-band to the next priority band (e.g.,Ka-band). If no switch is needed, the process can return to step 801(which can be skipped if no new parameters are needed, e.g. if the userhas not requested to change a parameter). If a switch is needed, theprocess may proceed to step 805.

In step 805, the antenna may switch to the new band. This may be done,for example, by automatically changing the switch 604 and switch 607,and requesting that the modem 701 use a different interface(610/611/612) for the communications to and from the consumer or userdevices.

From there, the process can return to step 801, and can repeatindefinitely.

The antenna can have active control of the azimuth, elevation andpolarization angles to maintain precise pointing towards the targetsatellite. The antenna can scan mechanically in both azimuth andelevation.

During operation with a geostationary satellite, the antenna can use abuilt-in GPS receiver to determine its position on the earth. It canthen use the geographical position and the stored (e.g., in localmemory) orbital location of the target satellite to determine theappropriate elevation angle. Once the elevation angle is set, theantenna can rotate in azimuth. During the scanning process the antennacan receive Eb/No information (e.g., signal to noise) from the modem toverify that the target satellite has been acquired. Once the satelliteis acquired, the antenna can dither in both azimuth and elevation by±2.0° to maintain peaking on the satellite and the transmission isenabled. The antenna may also include internal 3-axis gyroscopes and2-axis inclinometers to help with the tracking while the antenna is inmotion. The antenna can use the information from the gyros to determinewhen the pointing offset has reached 2.0° and can initiate transmitmuting when this occurs within 100 milliseconds. In alternativeembodiments, electronic beam steering can be used by the controllerafter the satellite is acquired to maintain peaking on the satellitewhile the system is in motion.

Although example embodiments are described above, the various featuresand steps may be combined, divided, omitted, and/or augmented in anydesired manner, depending on the specific secure process desired. Forexample, the antenna system can include circuitry to support multipledifferent bands beyond the examples described. It can also supportdifferent services in the same band. For example, if two differentcompetitors offer L-band communication services, the antenna system canswitch between the two based on the parameters, and can switch to tracka different satellite but in the same band.

We claim:
 1. An antenna system, comprising: a low-volume enclosure; amotor-driven rotatable assembly within the enclosure; and a flat panelarray antenna.